From the article:
Dr. Roderic Eckenhoff, a professor of anesthesia at the University of Pennsylvania, said the study is interesting but lacked rigor. “I would consider this a pilot study that maybe somebody should pick up on and do a more complete trial,” said Eckenhoff, who was not involved in the research.
One factor that bothered him was that the study was retrospective: The researchers simply examined medical records and compared whatever amount of sedation was used for each patient instead of controlling exact amounts of sedation and comparing the effects.
What is considered “enough” depends a lot on the individual providers and surgeons involved, Eckenhoff said. This “uncertainty” combined with a small number — just 25 — of cannabis-using patients makes the results “really tenuous at best,” he said.
Similar results have not been seen in previous research, he said: “Even if you give someone propofol for a long time, they get a little tolerant to it, but not by 200%.” Although upward of 200% “resistance” may be “possible, I’d be surprised if that held up in a bigger study,” he said.
Finally, he noted that patients are not always reliable and don’t necessarily tell their doctors about “everything else that they take,” and this may have influenced the results: “Some people who use marijuana also take other drugs recreationally.”
Or maybe marijuana users actually do have less tolerance for pain, because they experience it less often.